1. Field of the Invention
The present invention relates to a knowledge engineering system such as an expert system, and more particularly to an inference method suitable when facts are not initially given.
2. Description of the Related Art
As discussed in "LISP" by Winston and Horn, translated by Shirai and Abe, published by Baifu-kan (1982), forward reasoning is designed to operate when one or more facts are initially given, and facts not initially given are determined to be negated.
In the above prior art technique, some facts must be initially entered before inference, and facts not initially entered are interrupted to be negated till they are asserted by the inferencer. Accordingly, correct inference is not attained unless the facts are exactly cited.